docs: def get_offsets(self):
          """
          returns
          -------
          a dictionary with these entries
  
          header_start:
              byte offset from beginning of the file to the start
              of the header
          data_start:
              byte offset from beginning of the file to the start
              of the data section
          data_end:
              byte offset from beginning of the file to the end
              of the data section
  
          Note these are also in the information dictionary, which
          you can access with get_info()
          """
          return dict(
              header_start=self._info['header_start'],
              data_start=self._info['data_start'],
              data_end=self._info['data_end'],
          )